In many communications systems, such as telephone communications systems for example, a switching function is performed enabling one part to communicate with another party. In fact, a telephone central office is a switching system which switches a caller to a desired called party out of a choice of many other parties. With modern electronic telephone systems, each telephone subscriber can have his own switching system whereby several lines can be connected to the switching system for calls among and between the various lines.
In a digital telephone system it is customary to provide PCM switching functions for the telephone lines. A space and time switch can provide these PCM switching functions for a system. The PCM encoded data for the subscriber terminates at and originates from the space and time switch. It is a space and time switch that facilitates connecting any input to any output. Because the space and time switch is fragile, brittle, and performs many switching functions, it can be expensive employing many large scale integrated circuits or complicated circuitry. Accordingly, it will be understood that it would be highly desirable to provide a space and time switch that uses standard small and medium scale integrated circuits to provide a low power, one or two board space and time switching function module which can be controlled via a simple parallel interface.